Celiac disease, also called "sprue" and "gluten-sensitive enteropathy," is a chronic,
lifelong condition in which certain cereal proteins in the diet lead to injury of
the lining of the small intestine, or bowel. Gluten is an insoluble protein found
in wheat, rye, and other grains. The cause of celiac disease is not clearly understood.
A complex interaction between genetic and environmental factors causes celiac disease
to develop in susceptible people who include wheat, rye, and barley cereals in their
diet. An unknown third factor, possibly an infection or other triggering stimulus,
may be required since many people with similar risk factors do not develop celiac
disease.

Who gets celiac disease?

Celiac disease affects all ethnic groups. Most frequently affected are Caucasians,
then Blacks, and, only rarely, Orientals. Based on blood tests, about 1% of the
European population has evidence of celiac disease, and preliminary data suggests
the same is true in the United States. Most people with celiac disease have a certain
genetic type, which can be detected by screening. Although present in about 35%
of the general U.S. population, over 90% of patients with celiac disease have this
genetic type. How this genetic type predisposes individuals to developing celiac
disease is unclear. Groups at risk for celiac disease include those with:

type 1 diabetes (5% to 10% have celiac disease),

a first-degree relative with type 1 diabetes or celiac disease (2% to 7% have celiac disease),

Down syndrome,

dermatitis herpetiformis (a skin rash),

IgA deficiency (a lack of the chief antibody in the mucous membranes of the gastrointestinal tract),

How does celiac disease cause disease?

Illness from celiac disease generally comes from two processes: injury to the intestine
and from chronic inflammation. Upon biopsy (i.e., the removal of a small amount
of tissue and/or fluid from a living body and its examination to confirm the presence
of a disease), the small bowel injury has a typical appearance. White blood cells
(lymphocytes) enter the lining of the small bowel. The usual ridges, like tall mountains
and valleys, may become blunted, like small hills, or even flat, like the plains.
The injured small bowel may lead to diarrhea and impaired absorption. Over time,
nutritional deficiencies may develop, leading to poor growth; weight loss; short
stature; delayed puberty; anemia; and a lack of "micronutrients," including vitamins
A, E, and K; iron; zinc; and folic acid.

The second mechanism, chronic inflammation, may lead to a long-lasting ill feeling,
with poor appetite, and possibly bone thinning and easy fractures, called osteoporosis.
An eventual loss of regulation over the immune response has been thought to play
a role in the increased risk for small bowel lymphoma noted in untreated celiac
disease.

A similar inflammatory reaction may occur in the skin causing an itchy, scaly rash,
called dermatitis herpetiformis, and is a non-intestinal indication of gluten sensitivity.

What are the common findings of celiac disease?

Celiac disease can be thought of as occurring in two forms: "symptomatic" and "silent."
Both have positive blood tests for celiac disease-associated antibodies, and both
have a typical injury on biopsy of the small intestine. In the symptomatic form,
typical signs and symptoms are present. The most information about celiac disease
is known from this type. Common findings include abdominal pain, chronic diarrhea
with poor fat absorption (characterized as oily or greasy stools), vomiting, and
nutritional deficiencies (iron deficiency anemia, bleeding due to vitamin K deficiency,
and deficiencies of folic acid and zinc). Other findings include poor weight gain,
weight loss, short stature, delayed puberty, abdominal distention and gas, and,
in toddlers, irritability and edema (swelling of the feet, eyelids, and other soft
tissues).

In contrast, affected individuals with the silent type feel fine, have mild or no
symptoms, and do not know they have celiac disease. Less is known about silent celiac
disease; although, it is about six times more common than symptomatic celiac disease.
Whether silent celiac disease is a risk for the long-term complications seen in
symptomatic celiac disease is unknown.

How is celiac disease diagnosed?

Most experts agree that if both the blood test and the small intestine biopsy are
positive, then the diagnosis of celiac disease is made. The available blood tests
include anti-endomyseal antibody, anti-gliadin antibody, and, the newest one, anti-transglutaminase
antibody. These tests may be used separately or together, and are highly accurate
in screening individuals for celiac disease. However, rarely, the antibody tests
can be negative, especially in individuals with IgA deficiency and in young children.

A key in the proper diagnosis of celiac disease is improvement after starting a
gluten-free diet. Symptoms should resolve, the antibody tests should become negative
after 6 to 12 months of a strict gluten-free diet, and the small bowel injury should
resolve completely. In difficult diagnostic cases, screening for DQ-2, the genetic
marker of celiac disease, may be helpful. Previously, rechallenging the body with
gluten to show a reappearance of the symptoms was required to diagnose celiac disease;
but, now, it is rarely needed.

How is celiac disease treated?

Treatment for celiac disease first involves replacing deficient nutrients and choosing
a gluten-free diet. If patients-especially toddlers-are severely ill, a short course
of prednisone improves symptoms quickly. A lifelong gluten-free diet is the treatment
for celiac disease. A gluten-free diet means avoiding foods containing wheat, rye,
and barley proteins. Pure oats is probably allowable. Following a gluten-free diet
is quite challenging, as these products are widespread in Western diet. However,
within one week of the diet, irritability resolves, and appetite and energy level
improve. Many people with silent celiac disease report feeling healthy for the first
time, even though they never before complained of symptoms. If a gluten-free diet
is not followed, celiac disease will always recur; however, it may take weeks to
months.

How do you prevent celiac disease?

What research is being done?

Current research includes: identifying risk groups for celiac disease; understanding
the genetic predisposition and environmental triggers for developing celiac disease;
and determining how silent celiac disease is similar to and different from symptomatic
celiac disease, especially regarding growth, osteoporosis, and intestinal malignancy.

Are there other links to more information?

The Web site for the North American Society for Pediatric Gastroenterology and Nutrition, www.naspgn.org/disease_information.htm, provides information from pediatric gastroenterologists with sections for parents and for children. There is a nice section on foods that are "gluten-free"

Dr. Hoffenberg is on staff at the Children's Hospital in Denver, the University of Colorado School of Medicine, and is the Director at the Center for Pediatric Inflammatory Bowel Diseases. His areas of specialty include Inflammatory Bowel Disease, Celiac Disease and Polyps.